author = "Andrades Filho, Cl{\'o}dis de Oliveira and Rossetti, Dilce de 
                         F{\'a}tima and Bezerra, Francisco Hil{\'a}rio and Medeiros, 
                         Walter Eug{\^e}nio and Valeriano, M{\'a}rcio de Morisson and 
                         Cremon, {\'E}dipo Henrique and Oliveira, Roberto Gusm{\~a}o de",
          affiliation = "{} and {Instituto Nacional de Pesquisas Espaciais (INPE)} and {} 
                         and {} and {Instituto Nacional de Pesquisas Espaciais (INPE)} and 
                         {Instituto Nacional de Pesquisas Espaciais (INPE)}",
                title = "Mapping Neogene and Quaternary sedimentary deposits in 
                         northeastern Brazil by integrating geophysics, remote sensing and 
                         geological field data",
              journal = "Journal of South American Earth Sciences",
                 year = "2014",
               volume = "56",
                pages = "316--327",
                month = "Dec.",
             keywords = "Barreiras Formation, Post-Barreiras sediments, Gamma-ray, 
             abstract = "Neogene and late Quaternary sedimentary deposits corresponding 
                         respectively to the Barreiras Formation and Post-Barreiras 
                         Sediments are abundant along the Brazilian coast. Such deposits 
                         are valuable for reconstructing sea level fluctuations and 
                         recording tectonic reactivation along the passive margin of South 
                         America. Despite this relevance, much effort remains to be 
                         invested in discriminating these units in their various areas of 
                         occurrence. The main objective of this work is to develop and test 
                         a new methodology for semi-automated mapping of Neogene and late 
                         Quaternary sedimentary deposits in northeastern Brazil integrating 
                         geophysical and remote sensing data. The central onshore 
                         Para{\'{\i}}ba Basin was selected due to the recent availability 
                         of a detailed map based on the integration of surface and 
                         subsurface geological data. We used airborne gamma-ray 
                         spectrometry (i.e., potassium-K and thorium-Th concentration) and 
                         morphometric data (i.e., reliefdissection, slope and elevation) 
                         extracted from the digital elevation model (DEM) generated by the 
                         Shuttle Radar Topography Mission (SRTM). The procedures included: 
                         (a) data integration using geographic information systems (GIS); 
                         (b) exploratory statistical analyses, including the definition of 
                         parameters and thresholds for class discrimination for a set of 
                         sample plots; and (c) development and application of a 
                         decision-tree classification. Data validation was based on: (i) 
                         statistical analysis of geochemical and airborne gamma-ray 
                         spectrometry data consisting of K and Th concentrations; and (ii) 
                         map validation with the support of a confusion matrix, overall 
                         accuracy, as well as quantity disagreement and allocation 
                         disagreement for accuracy assessment based on field points. The 
                         concentration of K successfully separated the sedimentary units of 
                         the basin from Precambrian basement rocks. The reliefdissection 
                         morphometric variable allowed the discrimination between the 
                         Barreiras Formation and the Post-Barreiras Sediments. In addition, 
                         two units of the latter (i.e., PB1 and PB2) previously mapped in 
                         the field were promptly separated based on Th concentration. A 
                         regression analysis indicated that the relationship between 
                         geophysical and geochemical values obtained for the PB1, PB2 and 
                         Barreiras Formation is significant (R-squared = 0.91; p-value 
                         <0.05). Map validation presented a high overall accuracy of 84%, 
                         with a coefficient of quantity disagreement of 12% and a 
                         coefficient of allocation disagreement of 8%. These results 
                         indicate that the methodology applied in the central onshore 
                         Para{\'{\i}}ba Basin can be successfully used for mapping the 
                         Barreiras Formation and Post-Barreiras Sediments in other areas of 
                         the Brazilian coast. The ability to rapidly and precisely map 
                         these units using such methodology could reveal their geographic 
                         distribution along the northeastern coast of Brazil.",
                  doi = "10.1016/j.jsames.2014.09.018",
                  url = "http://dx.doi.org/10.1016/j.jsames.2014.09.018",
                 issn = "0895-9811",
                label = "lattes: 0307721738107549 2 AndradesFoRoBeMeVaCrOl:2014:MaNeQu",
             language = "en",
           targetfile = "1-s2.0-S0895981114001308-clodis.pdf",
        urlaccessdate = "01 dez. 2020"